Vryonis, Speros jr..
The decline of medieval hellenism in Asia Minor and the process of islamization from the eleventh through the fifteenth century /
Speros Vryonis, Jr. 
. - Berkeley : Los Angeles : London : University of California Press,  1971 
. - xvii, 532 p.  24 cm. 
 - (Publications of the Center for Medieval and Renaissan )